Polymethine dyestuffs and process of preparing them



Patented Sept. 25, 1945 POLYMIETHINE- DYESTUFFS AND PROCESS OF PREPARING THEM Hans von Freyberg and lleinrlch Koch, Frankiort-on-the-Main, Germany, assignors to General Aniline & Film Corporation, New York, N. Y., a corporation of Delaware No Drawing. Application July 24, 1940-, Serial No. 847,302. In Germany August 17, 1939 2 Claims.

methylene group with a paradialkylaminophenyl aldehyde the general formula:

(Para) /N-phenyl-CHO wherein R1 and R: represent alkyl radicals the total number of the carbon atoms of both alkyl radicals being together at least 7 and not more than 10, and wherein the phenyl radical may contain substituents.

The new dyestuffs thus obtained have the general formula.

R1 (Para) N-phenyl-CH=C=X wherein R1 and R: stand for alkyl radicals the total number of the carbon atoms of both alkyl radicals being together at least '7 and not more than 10, the grouping =C=X stands for the radical of a compound containing a reactive methylene group, in which the =C= portion is formed from the reactive methylene group and wherein the phenyl radical may contain substituents.

By the term reactive methylene group, a methylene group is to be understood which will condense with one aldehyde group by splitting oil water, with the formation of a carbon-carbon double linkage.

As suitable compounds with reactive methylene groups there may be mentioned, for example,

' derivatives of cyanacetic acid, such as their esters, ethers and amides, derivatives of malonic acid such as malonic nitrile, malonic ester or the like, pyrazolones, indolin es, oxindoles and the like.

The new dyestufis are distinguished by a number of improved iastness properties in comparison with analogous polymethine dyestuffs hitherto known.

' They go on to the fiber in an excellent manner and possess an improved Iastness to water, washing and to light. They are particularly suitable for dyeings on acetate silk. Thus, for instance, the dyestufl obtained according to the present invention by condensing para-N-butylisobutyl-aminobenzaldehyde and cyanacetic acid ethyl ester has an improved fastness to water over the known dyestuff from para-dimethylaminobenzaldehyde and cyanacetic acid ethyl ester and an improved affinity for acetate silk in comparison with the known dyestufl from para butyl-beta-chioroethyl-aminobenzaldehyde and cyanacetlc acid ethyl ester.

The new dyestuffs are also suitable for dyeing mordanted, for instance tanned cotton. Some of the new dyestuffs may be transformed into last lakes bymeans of complex phosphotungstic acids.

The following examples serve to illustrate the invention, but they are not intended to limit it thereto, the parts being by weight:

1. 114 parts of cyanacetic acid ethyl ester are heated to boiling for several hours with 235 parts of para N butyl isobutyl-amlnobenzaldehyde boiling between 177 C. and179 C. under a pressure of 1.7 mm. (obtainable according to known processes by causing N-butylisobutylaniline to react with methylformanilide and phosphorus oxychloride) in 400 parts of alcohol, while adding 0.4 part of piperidine until the formation of the dyestuif is complete. The alcohol is then distilled off; after some time the dyestufl crystallizes in the form or brown-yellow crystal druses melting at 51 C. to 53 C.

The dyestuff has the following formula:

HaC.CHa.CH:.CHz gN It dyes cellulose esters and cellulose ethers very clear greenish-yellow tints. It possesses an excellent aflinity for acetate silk fiber, very good fastness to wet processing and a very good fastness to light.

The N-butyl-isobutylaniline may be prepared in known manner, of., Zentralblatt 1926,11, page 391, Berichte der deutschen chemischen Gesellschaft, page 1202 et seq. It boils at 142 C. under a pressure of 11 mm.

2. parts of cyanacetic acid methyl ester are heated to boiling for several hours with 235 parts para-N-methyl-isoheptylaminobenzaldehyde boiling under a pressure of 1.4 mm. at a temperature of to 180 C. (obtainable in a manner idine.

analogous to that described in Example 1) in 400 parts of methanol, while adding 0.4 part of piperidine. When the formation of the dyestufi has ceased the whole is distilled with steam until the -methanol and the piperidine are expelled. The

dyestufl which is insoluble in water is separated.

Itvdyes cellulose esters and cellulose ethers very mo CN \v-O-cnmg Isoheptyl $000.11.

The base which is necessary for the preparation of the aldehyde was prepared, according to known processes, from isoheptyl-alcohol, aniline and hydrochloric acid and by methylating the monoisoheptylaniline obtained. It boils at 120 C. under a pressure of 1'7 mm.

3. 66 parts of malonic acid dinitrile are heated to boiling for several hours with 247 parts of para-N-methyl-iso-octyl amino benzaldehyde boiling at a temperature between 187 C. and 194 C. (prepared in a manner analogous to that described in Example 1) in 300 parts of alcohol, while adding 0.3 part of piperidine. When the formation of the dyestufl is complete the whole is distilled with steam until alcohol and piperidine have passed over. The dyestufl is filtered with suction. It has a very good afllnity for cellulose esters and cellulose ethers which are dyed bright yellow tints and possesses very good fastness properties. It has the formula:

Iso-octyl The methyl-iso-octyl-aniline ecessary for th! preparation of the aldehyde was produced by known processes from methylaniline and isooctyl-bromide. It boils at a temperature of 112 C. to 114 C. under a pressure of 1.3 mm.

4. 147 parts of N-methyloxindole are heated to boiling for several hours with 247 parts of para- N-methyl-iso-octyl-aminobenzaldehyde in 500 parts of alcohol, while adding 0.5 part of piper- When the formation of the dyestufi has ceased the alcohol is distilled off. The dyestufl separates in the form of crystals. It has a very good afiinity for cellulose esters and cellulose ethers which are dyed reddish-yellow-tints and is distinguished by an excellent fastness to wet processing. The dyestufr has the formula:

Hsc

Iso-octyl tion. When dried, the dyestufl forms scales having a bronze lustre. It dyes cellulose esters and cellulose ethers very brilllant red-violet tints and is especially distinguished by an excellent fastness to wet processing. It has the following formula:

The iso-octyl-oxethyl-meta-toluidine necessary for the preparation of the aldehyde was prepared, according to known processes. from meta-toluidine and iso-octyl-bromide and treating under pressure the mono-iso-octyl-meta-toluidine with ethylene oxide. It boils at a temperature between 157 C. to C. under a pressureof 4 mm.

6. 203 parts of 5-methoxy-1.3.3-trimethyl-2- methyleneindoline and 234 parts of para-N- ethyl-isoamylamino-ortho-tolylaldehyde boiling at a temperature between 177 C. to 180 C. under a pressure of 3.4 mm. (prepared in a manner analogous to that described in Example 1) are heated to boiling for several hours in 700 parts of glacial acetic acid. When the dyestufi formation is complete the dyestufl? solution is added to strong hydrochloric acid and salted out by means of a sodium chloride solution. After drying the dyestufl is obtained in the form of a resin having a' bronze luster which readily dissolves in water and readily dyes cellulose esters and cellulose ethers red-violet tints. The dyestufl is distinguished by an excellent fastness to wet processing and by a very good rastness to light. It has the I formula:

H 0 H C C K a f -0 CH:

/N CH=CH- Isoamyl /N\ H1O C1 The base necessary for the preparation of the aldehyde was produced by known methods from ethyl-meta-toluidine and isoamylbromide. It boils at 134 C. under a pressure of 12 mm.

7. 173 parts of 1.3.3-trimethyl-2-methlyeneindoline and 269 parts of para-N-met-hyl-isoheptyl-amino-ortho-chlorobenzaldehyde boiling at a temperature between C. and 196 C. under a pressure of 3 mm. (prepared in a manner analogous to that described in Example 1) are heated to 70 C. to 80 C. in 900 parts of glacial acetic acid until the formation of the dyestuff is complete. The solution of the dyestufl is then added to strong phosphoric acid and salted out with acid sodium phosphate. When dried the dyestufi forms a resin of a bronze luster which is readily soluble in water and dyes cellulose esters and cellulose ethers bluish-red tints having a very good fastness to wet processin The dyestuil has the formula:

The base necessary for the production oi. the

aldehyde was prepared, according to known procmember or the group consisting of isoamyl, isoesses; from 'meta-chloroaniline, isoheptyl alcohol octyl, and isoheptyl groups; Y is a member of the and hydrochloric acid and by methylating the roup consisting of hydrogen and methoxy; AN monoisoheptyl-meta-chloroaniline obtained. It means anion; and ALK means alkyl which dye boils at a temperature between 145 C. and 150 6 acetate silk red-violet and bluish-red tints.

C. under a pressure of 2.5 mm. 2. The dyestufl! oi. the formula:

We claim: f mo 1. The dyestuffs o the formula Hi0 k Inc-o 0cm Y N CE=CHJJ i \N honyl-CH-GH-L H p mo 01 dyeing acetate silk red-violet tints. ALK AN; wherein R1 is a member or the group consisting HANS vox FREYBERG.

of methyl, ethyl, and chloroethyl groups; R: is a HEINRICH KOCH. 

